This invention relates to an apparatus for use in exercising of the abdominal muscles.
A flat stomach is not only aesthetically pleasing but also indicates that an individual has the abdominal strength necessary to prevent some types of low back pain. A flat stomach is an objective of nearly all exercise programs. The sit-up, also known as the abdominal curl, is the most popular exercise one can do in effort to flatten the abdomen. Other exercises purporting to strengthen the abdominal muscles first rise in favour and then often fall into disuse because of their ineffectiveness or because they are difficult to perform.
A major problem facing designers of abdominal exercises is that the forward bending trunk movement necessary to strengthen the abdominal muscles (principally the rectus abdominis) can be done more powerfully by the psoas major and iliacus--two muscles that are under greater tension than the rectus. Although these two muscles are powerful hip and thigh flexors, they attach to the lumbar spine area and rear of the pelvis and to the hip bone. When they contract, not only does the rectus work with little effort, but these other two muscles rotate the pelvis forward; thus creating a situation that can increase low back pain, contribute to poor mechanical alignment, and produce an undesirable sway-backed, duck-footed posture. In the conventional sit-up, if the feet are locked under an object to obtain leverage, the strong leg muscles (quadriceps femoris) will also substitute for the abdominals.